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1.
Yale J Biol Med ; 97(2): 205-224, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38947104

RESUMO

Neuroinflammation, toxic protein aggregation, oxidative stress, and mitochondrial dysfunction are key pathways in neurodegenerative diseases like Alzheimer's disease (AD). Targeting these mechanisms with antioxidants, anti-inflammatory compounds, and inhibitors of Aß formation and aggregation is crucial for treatment. Marine algae are rich sources of bioactive compounds, including carbohydrates, phenolics, fatty acids, phycobiliproteins, carotenoids, fatty acids, and vitamins. In recent years, they have attracted interest from the pharmaceutical and nutraceutical industries due to their exceptional biological activities, which include anti-inflammation, antioxidant, anticancer, and anti-apoptosis properties. Multiple lines of evidence have unveiled the potential neuroprotective effects of these multifunctional algal compounds for application in treating and managing AD. This article will provide insight into the molecular mechanisms underlying the neuroprotective effects of bioactive compounds derived from algae based on in vitro and in vivo models of neuroinflammation and AD. We will also discuss their potential as disease-modifying and symptomatic treatment strategies for AD.


Assuntos
Doença de Alzheimer , Microalgas , Alga Marinha , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Humanos , Microalgas/química , Microalgas/metabolismo , Alga Marinha/química , Animais , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Produtos Biológicos/isolamento & purificação , Antioxidantes/farmacologia
2.
Sci Rep ; 14(1): 14984, 2024 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-38951587

RESUMO

Sea-ice microalgae are a key source of energy and nutrient supply to polar marine food webs, particularly during spring, prior to open-water phytoplankton blooms. The nutritional quality of microalgae as a food source depends on their biomolecular (lipid:protein:carbohydrate) composition. In this study, we used synchrotron-based Fourier transform infra-red microspectroscopy (s-FTIR) to measure the biomolecular content of a dominant sea-ice taxa, Nitzschia frigida, from natural land-fast ice communities throughout the Arctic spring season. Repeated sampling over six weeks from an inner (relatively stable) and an outer (relatively dynamic) fjord site revealed high intra-specific variability in biomolecular content, elucidating the plasticity of N. frigida to adjust to the dynamic sea ice and water conditions. Environmental triggers indicating the end of productivity in the ice and onset of ice melt, including nitrogen limitation and increased water temperature, drove an increase in lipid and fatty acids stores, and a decline in protein and carbohydrate content. In the context of climate change and the predicted Atlantification of the Arctic, dynamic mixing and abrupt warmer water advection could truncate these important end-of-season environmental shifts, causing the algae to be released from the ice prior to adequate lipid storage, influencing carbon transfer through the polar marine system.


Assuntos
Camada de Gelo , Estações do Ano , Regiões Árticas , Mudança Climática , Microalgas/metabolismo , Diatomáceas/metabolismo , Diatomáceas/fisiologia , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Fitoplâncton/metabolismo , Fitoplâncton/fisiologia
3.
Sci Rep ; 14(1): 15032, 2024 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-38951590

RESUMO

In agriculture, hydrogels can be addressed for effective operation of water and controlled-release fertilizers. Hydrogels have a significant ability for retaining water and improving nutrient availability in soil, enhancing plant growth while reducing water and fertilizer usage. This work aimed to prepare a hydrogel composite based on microalgae and biopolymers including chitosan and starch for use as a soil conditioner. The hydrogel composite was characterized by FTIR, XRD, and SEM. All hydrogel properties were studied including swelling degree, biodegradability, water-holding capacity, water retention, and re-swelling capacity in soil and water. The urea fertilizer loading and releasing behavior of the prepared hydrogels were investigated. The results revealed that the range of the maximal urea loading was between 99 and 440%, and the kinetics of loading was fitted with Freundlich model. The urea release % exhibited 78-95%, after 30 days, and the kinetics of release was fitted with zero-order, Higuchi, and Korsmeyer-Peppas models. Furthermore, the prepared hydrogels obtained a significant water-holding capacity, after blending soil (50 g) with small amount of hydrogels (1 g), the capacity increased in the range of 99.4-101.5%. In sum, the prepared hydrogels have the potential to be applied as a soil conditioner.


Assuntos
Fertilizantes , Hidrogéis , Microalgas , Ureia , Fertilizantes/análise , Hidrogéis/química , Ureia/química , Microalgas/química , Preparações de Ação Retardada/química , Cinética , Água/química , Solo/química , Quitosana/química , Amido/química
4.
J Environ Sci (China) ; 146: 272-282, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38969455

RESUMO

Further treatment of secondary effluents before their discharge into the receiving water bodies could alleviate water eutrophication. In this study, the Chlorella proteinosa was cultured in a membrane photobioreactor to further remove nitrogen from the secondary effluents. The effect of hydraulic retention time (HRT) on microalgae biomass yields and nutrient removal was studied. The results showed that soluble algal products concentration reduced in the suspension at low HRT, thereby alleviating microalgal growth inhibition. In addition, the lower HRT reduced the nitrogen limitation for Chlorella proteinosa's growth through the phase-out of nitrogen-related functional bacteria. As a result, the productivity for Chlorella proteinosa increased from 6.12 mg/L/day at an HRT of 24 hr to 20.18 mg/L/day at an HRT of 8 hr. The highest removal rates of 19.7 mg/L/day, 23.8 mg/L/day, and 105.4 mg/L/day were achieved at an HRT of 8 hr for total nitrogen (TN), ammonia, and chemical oxygen demand (COD), respectively. However, in terms of removal rate, TN and COD were the largest when HRT is 24 hr, which were 74.5% and 82.6% respectively. The maximum removal rate of ammonia nitrogen was 99.2% when HRT was 8 hr.


Assuntos
Biomassa , Chlorella , Nitrogênio , Fotobiorreatores , Eliminação de Resíduos Líquidos , Nitrogênio/metabolismo , Chlorella/metabolismo , Chlorella/crescimento & desenvolvimento , Eliminação de Resíduos Líquidos/métodos , Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo , Eutrofização
5.
Sci Adv ; 10(27): eadn8356, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38968348

RESUMO

Eukaryotic phytoplankton, also known as algae, form the basis of marine food webs and drive marine carbon sequestration. Algae must regulate their motility and gravitational sinking to balance access to light at the surface and nutrients in deeper layers. However, the regulation of gravitational sinking remains largely unknown, especially in motile species. Here, we quantify gravitational sinking velocities according to Stokes' law in diverse clades of unicellular marine microalgae to reveal the cell size, density, and nutrient dependency of sinking velocities. We identify a motile algal species, Tetraselmis sp., that sinks faster when starved due to a photosynthesis-driven accumulation of carbohydrates and a loss of intracellular water, both of which increase cell density. Moreover, the regulation of cell sinking velocities is connected to proliferation and can respond to multiple nutrients. Overall, our work elucidates how cell size and density respond to environmental conditions to drive the vertical migration of motile algae.


Assuntos
Tamanho Celular , Nutrientes , Nutrientes/metabolismo , Gravitação , Fitoplâncton/fisiologia , Fitoplâncton/metabolismo , Fotossíntese , Microalgas/metabolismo
6.
Arch Microbiol ; 206(8): 343, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38967670

RESUMO

Environmental pollution poses a critical global challenge, and traditional wastewater treatment methods often prove inadequate in addressing the complexity and scale of this issue. On the other hand, microalgae exhibit diverse metabolic capabilities that enable them to remediate a wide range of pollutants, including heavy metals, organic contaminants, and excess nutrients. By leveraging the unique metabolic pathways of microalgae, innovative strategies can be developed to effectively remediate polluted environments. Therefore, this review paper highlights the potential of microalgae-mediated bioremediation as a sustainable and cost-effective alternative to conventional methods. It also highlights the advantages of utilizing microalgae and algae-bacteria co-cultures for large-scale bioremediation applications, demonstrating impressive biomass production rates and enhanced pollutant removal efficiency. The promising potential of microalgae-mediated bioremediation is emphasized, presenting a viable and innovative alternative to traditional treatment methods in addressing the global challenge of environmental pollution. This review identifies the opportunities and challenges for microalgae-based technology and proposed suggestions for future studies to tackle challenges. The findings of this review advance our understanding of the potential of microalgae-based technology wastewater treatment.


Assuntos
Biodegradação Ambiental , Microalgas , Águas Residuárias , Microalgas/metabolismo , Águas Residuárias/microbiologia , Águas Residuárias/química , Metais Pesados/metabolismo , Biomassa , Bactérias/metabolismo , Bactérias/genética , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos
7.
Braz J Biol ; 84: e278486, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38985059

RESUMO

The present study evaluated the hematological, antiparasitic and growth responses in tambaqui (Colossoma macropomum) fed with diets supplemented with the microalgae Arthrospira platensis and Chlorella vulgaris (0%; 10% A. platensis; 10% C. vulgaris; and 5% A. platensis+5% C. vulgaris). Tambaqui (n=60, 62.57 ± 8.76 g) were fed for 20 days with experimental diets. Blood samples collection was done to determine hematological parameters, and gills were removed to identify and count monogenetic parasites. Supplementation with A. platensis 10% reduced red blood cells count, in consequence mean corpuscular volume and mean hemoglobin concentration increased. Total leukocyte, monocyte, eosinophil, and basophil counts reduced with the use of A. platensis. Higher monocytes, eosinophil, and basophil numbers in tambaqui fed with diet supplemented with 10% C. vulgaris were observed and may have been due to the presence of immunostimulants in this microalga composition. Reduction on total cholesterol in tambaqui that received both microalgae (A. platensis 5%+C. vulgaris 5%) may indicate that combined supplementation presented greater benefits to the health for C. macropomum than separately. Both microalgae were efficient against monogenetic parasites of tambaqui. Thus, the dietary use of the microalgae A. platensis and C. vulgaris provided immunostimulant and antiparasitic efficacy in C. macropomum.


Assuntos
Chlorella vulgaris , Spirulina , Chlorella vulgaris/química , Animais , Suplementos Nutricionais , Caraciformes , Microalgas/química
8.
Sci Rep ; 14(1): 16004, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38992288

RESUMO

The formation of symbionts by using different combinations of endophytic bacteria, microalgae, and fungi to purify antibiotics-containing wastewater is an effective and promising biomaterial technology. As it enhances the mixed antibiotics removal performance of the bio-system, this technology is currently extensively studied. Using exogenous supplementation of various low concentrations of the phytohormone strigolactone analogue GR24, the removal of various antibiotics from simulated wastewater was examined. The performances of Chlorella vulgaris monoculture, activated sludge-C. vulgaris-Clonostachys rosea, Bacillus licheniformis-C. vulgaris-C. rosea, and endophytic bacteria (S395-2)-C. vulgaris-C. rosea co-culture systems were systematically compared. Their removal capacities for tetracycline, oxytetracycline, and chlortetracycline antibiotics from simulated wastewater were assessed. Chlorella vulgaris-endophytic bacteria-C. rosea co-cultures achieved the best performance under 0.25 mg L-1 antibiotics, which could be further enhanced by GR24 supplementation. This result demonstrates that the combination of endophytic bacteria with microalgae and fungi is superior to activated sludge-B. licheniformis-microalgae-fungi systems. Exogenous supplementation of GR24 is an effective strategy to improve the performance of antibiotics removal from wastewater.


Assuntos
Antibacterianos , Microalgas , Microalgas/metabolismo , Antibacterianos/farmacologia , Chlorella vulgaris/metabolismo , Técnicas de Cocultura , Lactonas/metabolismo , Águas Residuárias/química , Águas Residuárias/microbiologia , Compostos Heterocíclicos com 3 Anéis/isolamento & purificação , Esgotos/microbiologia , Poluentes Químicos da Água , Biodegradação Ambiental , Purificação da Água/métodos
9.
Cells ; 13(13)2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38994989

RESUMO

The extensive metabolic diversity of microalgae, coupled with their rapid growth rates and cost-effective production, position these organisms as highly promising resources for a wide range of biotechnological applications. These characteristics allow microalgae to address crucial needs in the agricultural, medical, and industrial sectors. Microalgae are proving to be valuable in various fields, including the remediation of diverse wastewater types, the production of biofuels and biofertilizers, and the extraction of various products from their biomass. For decades, the microalga Chlamydomonas has been widely used as a fundamental research model organism in various areas such as photosynthesis, respiration, sulfur and phosphorus metabolism, nitrogen metabolism, and flagella synthesis, among others. However, in recent years, the potential of Chlamydomonas as a biotechnological tool for bioremediation, biofertilization, biomass, and bioproducts production has been increasingly recognized. Bioremediation of wastewater using Chlamydomonas presents significant potential for sustainable reduction in contaminants and facilitates resource recovery and valorization of microalgal biomass, offering important economic benefits. Chlamydomonas has also established itself as a platform for the production of a wide variety of biotechnologically interesting products, such as different types of biofuels, and high-value-added products. The aim of this review is to achieve a comprehensive understanding of the potential of Chlamydomonas in these aspects, and to explore their interrelationship, which would offer significant environmental and biotechnological advantages.


Assuntos
Biodegradação Ambiental , Chlamydomonas , Microalgas , Chlamydomonas/metabolismo , Microalgas/metabolismo , Biocombustíveis , Biomassa , Biotecnologia/métodos
10.
Planta ; 260(2): 39, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38951320

RESUMO

MAIN CONCLUSION: Nitrogen stress altered important lipid parameters and related genes in Chlorella pyrenoidosa via ROS and Ca2+ signaling. The mutual interference between ROS and Ca2+ signaling was also uncovered. The changed mechanisms of lipid parameters (especially lipid classes and unsaturation of fatty acids) in microalgae are not completely well known under nitrogen stress. Therefore, Chlorella pyrenoidosa was exposed to 0, 0.5, 1 and 1.5 g L-1 NaNO3 for 4 days. Then, the physiological and biochemical changes were measured. It was shown that the total lipid contents, neutral lipid ratios as well as their related genes (accD and DGAT) increased obviously while the polar lipid ratios, degrees of unsaturation as well as their related genes (PGP and desC) decreased significantly in nitrogen stress groups. The obvious correlations supported that gene expressions should be the necessary pathways to regulate the lipid changes in C. pyrenoidosa under nitrogen stress. The changes in ROS and Ca2+ signaling as well as their significant correlations with corresponding genes and lipid parameters were analyzed. The results suggested that ROS and Ca2+ may regulate these gene expressions and lipid changes in C. pyrenoidosa under nitrogen stress conditions. This was verified by the subordinate tests with an ROS inhibitor and calcium reagents. It also uncovered the clues of mutual interference between ROS and Ca2+ signaling. To summarize, this study revealed the signaling pathways of important lipid changes in microalgae under N stress.


Assuntos
Chlorella , Nitrogênio , Espécies Reativas de Oxigênio , Estresse Fisiológico , Chlorella/metabolismo , Chlorella/genética , Chlorella/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Nitrogênio/metabolismo , Metabolismo dos Lipídeos/genética , Cálcio/metabolismo , Lipídeos , Sinalização do Cálcio , Transdução de Sinais , Microalgas/metabolismo , Microalgas/genética
11.
Environ Sci Pollut Res Int ; 31(33): 46073-46086, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38980488

RESUMO

The rapid increase in aquaculture over the last several decades has led to concerns about the environmental impact of fish feeds relying on marine resources for fishmeal (FM). We aim to assess Nannochloropsis sp. QH25 co-product as a viable and sustainable replacement for FM in juvenile rainbow trout, Oncorhynchus mykiss, feeds. We formulated four experimental diets: a reference (FM based), 33N, 66N, and 100N diet (33%, 66%, and 100% co-product replacement). Rainbow trout were randomly assigned to one of 16 tanks and randomly assigned an experimental diet to consume throughout the experiment (64 days total), with four replicate tanks per diet. We compared the phosphorus (P) and nitrogen (N) digestibility, emissions, and growth between diets and, compared six environmental impacts (biotic resource use (BRU), global warming potential (GWP), water use, land use, marine eutrophication potential (MEP), and freshwater eutrophication potential (FEP)) of each diet. Our results indicate that replacing FM with co-product did not significantly alter growth. P digestibility of the experimental and reference diets was comparable. BRU conversion ratio was significantly lower in the experimental diets. However, there were significantly higher water and land use conversion ratios but insignificantly higher results in GWP, MEP, and FEP between the reference and 100N diet.


Assuntos
Ração Animal , Aquicultura , Microalgas , Oncorhynchus mykiss , Animais , Reciclagem , Nitrogênio
12.
Crit Rev Food Sci Nutr ; 64(20): 7149-7171, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38975868

RESUMO

Microalgae are booming as a sustainable protein source for human nutrition and animal feed. Nevertheless, certain strains were reported to have robust cell walls limiting protein digestibility. There are several disruption approaches to break down the cell integrity and increase digestive enzyme accessibility. This review's intent is to discuss the digestibility of microalgae proteins in intact cells and after their disruption. In intact single cells, the extent of protein digestibility is chiefly related to cell wall structural properties (differing among strains) as well as digestion method and when added to food or feed protein digestibility changes depending on the matrix's composition. The degree of effectiveness of the disruption method varies among studies, and it is complicated to compare them due to variabilities in digestibility models, strains, disruption method/conditions and their consequent impact on the microalgae cell structure. More exhaustive studies are still required to fill knowledge gaps on the structure of microalgal cell walls and to find efficient and cost-effective disruption technologies to increase proteins availability without hindering their quality.


Assuntos
Parede Celular , Digestão , Microalgas , Microalgas/química , Microalgas/metabolismo , Digestão/fisiologia , Humanos , Parede Celular/química , Parede Celular/metabolismo , Ração Animal/análise , Animais , Proteínas Alimentares/metabolismo
13.
PeerJ ; 12: e17659, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39006034

RESUMO

This work presents a low-cost, open-source turbidimeter, the 'Erlenmeter', designed to monitor the growth of microorganisms in batch cultures. It is easy to build, based exclusively on inexpensive off-the-shelf electronic components and 3D-printed parts. The Erlenmeter allows measuring the optical density of cultures on standard Erlenmeyer flasks without the need to open the flasks to collect aliquots, ensuring speed, minimal use of consumables, and elimination of the risk of contamination. These features make it particularly well-suited not just for routine research assays but also for experimental teaching. Here we illustrate the use of the Erlenmeter turbidimeter to record the growth of the microalga Phaeodactylum tricornutum, of the bacterium Escherichia coli, and of the yeast Saccharomyces cerevisiae, model organisms that are widely used in research and teaching. The Erlenmeter allows a detailed characterization of the growth curves of all organisms, confirming its usefulness for studying microbial populations dynamics both for research purposes and in classroom settings.


Assuntos
Escherichia coli , Nefelometria e Turbidimetria , Saccharomyces cerevisiae , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/isolamento & purificação , Saccharomyces cerevisiae/crescimento & desenvolvimento , Nefelometria e Turbidimetria/instrumentação , Nefelometria e Turbidimetria/métodos , Microalgas/crescimento & desenvolvimento , Fenótipo
14.
Environ Sci Technol ; 58(29): 12921-12932, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-38965053

RESUMO

Marine microalgae serve as an aquaculture bait. To enhance algal cell growth and breeding profits, high-intensity light conditions are standard for cultivating bait microalgae, potentially altering microalgal metabolite production. This research revealed that Thalassiosira pseudonana, when subjected to high-intensity light conditions, accumulated significant quantities of retinal (RAL) that transferred through the food chain and transformed into all-trans retinoic acid (atRA) in marine medaka. The study further explored the toxic effects on individual fish and specific tissues, as well as the mechanisms behind this toxicity. The accumulation of atRA in the liver, intestine, and spinal column resulted in structural damage and tissue inflammation, as well as oxidative stress. It also down-regulated the gene transcription levels of key pathways involved in immune function and growth. Furthermore, it disrupted the homeostasis of the intestinal microbial communities. The implications for wildlife and human health, which are influenced by the regulation of microalgal metabolite accumulation and their transfer via the food chain, require further investigation and could hold broader significance.


Assuntos
Cadeia Alimentar , Fígado , Oryzias , Animais , Oryzias/metabolismo , Fígado/metabolismo , Retinoides/metabolismo , Intestinos , Microalgas , Aquicultura
15.
Bioresour Technol ; 406: 131077, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38971386

RESUMO

Biomining using microalgae has emerged as a sustainable option to extract rare earth elements (REEs). This study aims to (i) explore the capability of REEs recovery from bauxite by microalgae, (ii) assess the change of biochemical function affected by bauxite, and (iii) investigate the effects of operating conditions (i.e., aeration rate, pH, hydraulic retention time) to REEs recovery. The results showed that increasing bauxite in microalgae culture increases REEs recovery in biomass and production of biochemical compounds (e.g., pigments and Ca-Mg ATPase enzyme) up to 10 %. The optimum pulp ratio of bauxite in the microalgae culture ranges from 0.2 % to 0.6 %. Chlorella vulgaris was the most promising, with two times higher in REEs recovery in biomass than the other species. REEs accumulated in microalgae biomass decreased with increasing pH in the culture. This study establishes a platform to make the scaling up of REEs biomining by microalgae plausible.


Assuntos
Óxido de Alumínio , Biomassa , Metais Terras Raras , Microalgas , Metais Terras Raras/metabolismo , Microalgas/metabolismo , Concentração de Íons de Hidrogênio , Chlorella vulgaris/metabolismo
16.
World J Microbiol Biotechnol ; 40(9): 272, 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39030303

RESUMO

Microalgae are a source of a wide variety of commodities, including particularly valuable pigments. The typical pigments present in microalgae are the chlorophylls, carotenoids, and phycobiliproteins. However, other types of pigments, of the family of water-soluble polyphenols, usually encountered in terrestrial plants, have been recently reported in microalgae. Among such microalgal polyphenols, many flavonoids have a yellowish hue, and are used as natural textile dyes. Besides being used as natural colorants, for example in the food or cosmetic industry, microalgal pigments also possess many bioactive properties, making them functional as nutraceutical or pharmaceutical agents. Each type of pigment, with its own chemical structure, fulfills particular biological functions. Considering both eukaryotes and prokaryotes, some species within the four most promising microalgae groups (Cyanobacteria, Rhodophyta, Chlorophyta and Heterokontophyta) are distinguished by their high contents of specific added-value pigments. To further enhance microalgae pigment contents during autotrophic cultivation, a review is made of the main related strategies adopted during the last decade, including light adjustments (quantity and quality, and the duration of the photoperiod cycle), and regard to mineral medium characteristics (salinity, nutrients concentrations, presence of inductive chemicals). In contrast to what is usually observed for growth-related pigments, accumulation of non-photosynthetic pigments (polyphenols and secondary carotenoids) requires particularly stressful conditions. Finally, pigment enrichment is also made possible with two new cutting-edge technologies, via the application of metallic nanoparticles or magnetic fields.


Assuntos
Microalgas , Pigmentos Biológicos , Microalgas/metabolismo , Microalgas/química , Pigmentos Biológicos/química , Carotenoides/química , Carotenoides/metabolismo , Carotenoides/análise , Ficobiliproteínas/química , Ficobiliproteínas/metabolismo , Cianobactérias/metabolismo , Cianobactérias/química , Rodófitas/química , Rodófitas/metabolismo , Clorófitas/química , Clorófitas/metabolismo , Clorofila/análise , Polifenóis/análise , Polifenóis/química , Polifenóis/metabolismo , Meios de Cultura/química
17.
World J Microbiol Biotechnol ; 40(9): 271, 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39030369

RESUMO

Microalgal biomass for biofuel production, integration into functional food, and feed supplementation has generated substantial interest worldwide due to its high growth rate, non-competitiveness for agronomic land, ease of cultivation in containments, and presence of several bioactive molecules. In this study, genetic engineering tools were employed to develop transgenic lines of freshwater microalga Chlorella vulgaris with a higher starch content, by up-regulating ADP-glucose pyrophosphorylase (AGPase), which is a rate-limiting enzyme in starch biosynthesis. Expression of the Escherichia coli glgC (AGPase homolog) gene in C. vulgaris led to an increase in total carbohydrate content up to 45.1% (dry cell weight, DCW) in the transgenic line as compared to 34.2% (DCW) in the untransformed control. The starch content improved up to 16% (DCW) in the transgenic alga compared to 10% (DCW) in the control. However, the content of total lipid, carotenoid, and chlorophyll decreased differentially in the transgenic lines. The carbohydrate-rich biomass from the transgenic algal line was used to produce bioethanol via yeast fermentation, which resulted in a higher ethanol yield of 82.82 mg/L as compared to 54.41 mg/L from the untransformed control. The in vitro digestibility of the transgenic algal starch revealed a resistant starch content of up to 7% of total starch. Faster growth of four probiotic bacterial species along with a lowering of the pH of the growth medium indicated transgenic alga to exert a positive prebiotic effect. Taken together, the study documents the utilization of genetically engineered C. vulgaris with enriched carbohydrates as bioethanol feedstock and functional food ingredients.


Assuntos
Biocombustíveis , Biomassa , Chlorella vulgaris , Escherichia coli , Etanol , Fermentação , Glucose-1-Fosfato Adenililtransferase , Microalgas , Prebióticos , Amido , Chlorella vulgaris/metabolismo , Chlorella vulgaris/crescimento & desenvolvimento , Etanol/metabolismo , Amido/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Microalgas/metabolismo , Microalgas/genética , Glucose-1-Fosfato Adenililtransferase/metabolismo , Glucose-1-Fosfato Adenililtransferase/genética , Engenharia Genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Engenharia Metabólica/métodos
18.
Sci Total Environ ; 946: 174352, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-38969108

RESUMO

Marine plastic debris (MPD) is a potential threat to marine ecosystems, but its function as a vector for the transportation of harmful microalgae and its impact on the habitats of other marine organisms are uncertain. To address this gap in knowledge, we performed month-long experiments in 30 L microcosms that contained plates made of six different plastic polymers (polypropylene [PP], low-density polyethylene [LDPE], high-density polyethylene [HDPE], polyvinyl chloride [PVC], polyethylene terephthalate [PET], and polystyrene [PS]), and examined the time course of changes in planktonic and periphytic microalgae. There were no significant differences in the composition of periphytic microalgae or biomass among the different plastic polymers (p > 0.05). Nutrient depletion decreased the abundance of planktonic microalgae, but increased the biomass of attached periphytic microalgae (p < 0.05). In particular, analysis of the plastic plates showed that the abundance of benthic species that are responsible for harmful algal blooms (HABs), such as Amphidinium operculatum and Coolia monotis, significantly increased over time (days 21-28; p < 0.05). Our findings demonstrated that periphyton species, including benthic microalgae that cause HABs, can easily attach to different types of plastic and potentially spread to different regions and negatively impact these ecosystems. These observations have important implications for understanding the potential role of MPD in the spread of microalgae, including HABs, which pose a significant threat to marine ecosystems.


Assuntos
Biomassa , Microalgas , Plásticos , Plásticos/análise , Proliferação Nociva de Algas , Poluentes Químicos da Água/análise , Nutrientes/análise , Monitoramento Ambiental , Ecossistema
19.
Sci Data ; 11(1): 780, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39013888

RESUMO

Euglena gracilis (E. gracilis), pivotal in the study of photosynthesis, endosymbiosis, and chloroplast development, is also an industrial microalga for paramylon production. Despite its importance, E. gracilis genome exploration faces challenges due to its intricate nature. In this study, we achieved a chromosome-level de novo assembly (2.37 Gb) using Illumina, PacBio, Bionano, and Hi-C data. The assembly exhibited a contig N50 of 619 Kb and scaffold N50 of 1.12 Mb, indicating superior continuity. Approximately 99.83% of the genome was anchored to 46 chromosomes, revealing structural insights. Repetitive elements constituted 58.84% of the sequences. Functional annotations were assigned to 39,362 proteins, enhancing interpretative power. BUSCO analysis confirmed assembly completeness at 80.39%. This first high-quality E. gracilis genome offers insights for genetics and genomics studies, overcoming previous limitations. The impact extends to academic and industrial research, providing a foundational resource.


Assuntos
Euglena gracilis , Euglena gracilis/genética , Cromossomos , Microalgas/genética , Anotação de Sequência Molecular , Glucanos
20.
BMC Vet Res ; 20(1): 321, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39026262

RESUMO

BACKGROUND: Identifying alternative sustainable feed sources with high nutritional values is crucial for the future of environmentally and socially responsible aquaculture. In this regard, microalgae have been proven to have positive effects on fish health, which overwhelmed our interest in this study. METHODS: Pediastrum boryanum (P. boryanum) was incorporated into Nile tilapia feed at concentrations of 0, 0.75, and 1.5 mg/kg, as control, PbExt0.75, and PbExt1.5 groups to assess its effects on growth and biochemical indices, oxidant/antioxidant activities, immune and stress-related gene expression, and intestinal morphology. RESULTS: After 8 weeks, fish fed P. boryanum supplemented feed exhibited significant increases in final weight, length, condition factor, body weight gain, and specific growth rate, while the spleen-somatic index (SSI) and hepatosomatic index (HSI) showed no significant differences compared to the control group. Dietary P. boryanum supplementation also enhanced IgM levels and lysozyme activity, along with no marked effect on markers of liver function enzymes (alanine aminotransferase/ALT and aspartate aminotransferase/AST) or protein status (total protein and albumin). Furthermore, P. boryanum addition increased the activity of superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) enzymes, highlighting its antioxidant potential, whereas malondialdehyde (MDA) concentrations showed no significant differences among the groups. Gene expression analysis revealed that tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), and transforming growth factor-ß1 (TGF-ß1) expression notably increased in groups fed P. boryanum containing feed, while no significant difference was observed in hepatic Heat Shock Protein 70 (HSP70) mRNA expression. Histopathological examination revealed no adverse effects of P. boryanum supplementation on the liver, spleen, or intestinal tissues. Villous height and villous surface area were notably increased in the high P. boryanum supplementation group, suggesting improved intestinal integrity and nutrient absorption. CONCLUSION: Dietary P. boryanum supplementation can potentially improve growth performance, immune response, antioxidant status, and intestinal health of Nile tilapia, making it a promising candidate for sustainable aquaculture.


Assuntos
Ração Animal , Ciclídeos , Dieta , Suplementos Nutricionais , Microalgas , Animais , Ciclídeos/imunologia , Ciclídeos/crescimento & desenvolvimento , Ração Animal/análise , Dieta/veterinária , Aquicultura , Antioxidantes/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Extratos Vegetais/farmacologia
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